About Pregnancy

Pregnancy is the term used to describe the period in which a fetus develops inside a woman's womb or uterus.

Pregnancy usually lasts about 40 weeks, or just over 9 months, as measured from the last menstrual period to delivery. Health care providers refer to three segments of pregnancy, called trimesters. The major events in each trimester are described below.1


  1. Office on Women's Health. (2010). Stages of pregnancy. Retrieved May 20, 2016, from http://womenshealth.gov/pregnancy/you-are-pregnant/stages-of-pregnancy.html
  2. American College of Obstetricians and Gynecologists (ACOG). (2015, June). Prenatal development: How your baby grows during pregnancy. Retrieved May 20, 2016, from http://www.acog.org/~/media/For%20Patients/faq156.pdf?dmc=1&ts=20120731T1026504777 External Web Site Policy (PDF - 70 KB)
  3. Stoll, B. J., Hansen, N. I., Bell, E. F., Shankaran, S., Laptook, A. R., Walsh, M. C., et al. (2010). Neonatal outcomes of extremely preterm infants from the NICHD Neonatal Research Network. Pediatrics, 126, 443–456. PMID: 20732945
  4. Spong, C. Y. (2013). Defining "term" pregnancy: Recommendations from the Defining "Term" Pregnancy Workgroup. JAMA, 309(13), 2445–2446. Retrieved October 28, 2013, from http://jama.jamanetwork.com/article.aspx?articleID=1685467 External Web Site Policy
  5. Centers for Disease Control and Prevention. (n.d.). CDC WONDER: About natality, 2007-2014. Retrieved May 20, 2016, from http://wonder.cdc.gov/natality-current.html
  6. ACOG Committee on Obstetric Practice and Society for Maternal-Fetal Medicine. (2013; Reaffirmed 2015). Committee Opinion No. 579. Definition of term pregnancy. Retrieved May 20, 2016, from http://www.acog.org/Resources_And_Publications/Committee_Opinions/
     External Web Site Policy
  7. NICHD. (2013). Carrying pregnancy to 39 weeks: Is it worth it? Yes! Retrieved July 8, 2016, from https://www.nichd.nih.gov/news/resources/spotlight/Pages/013113-NCMHEP-videos.aspx
  8. NICHD. (2013). Redefining the term. Retrieved July 8, 2016, from https://www.nichd.nih.gov/news/resources/spotlight/Pages/102413-redefining-term.aspx

What are some common signs of pregnancy?

How do I know if I'm pregnant?

What is prenatal care and why is it important?

What are some common complications of pregnancy?

What is a high-risk pregnancy?

What infections can affect pregnancy?

What is labor?

What is a cesarean delivery?

What should I know about postpartum depression?

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